SAR125844 is a potent and selective MET kinase inhibitor with a favorable preclinical toxicity profile,(IC50=4.2 nM).

MET RTK:4.2 nM

MKN-45, Hs 746T, and SNU-5 cells were seeded in poly d-lysine 96-well plates in complete medium. Plates were incubated with increasing SAR125844 concentrations for 1 hour, cell lysates were generated using standard procedures and pMETY1230/1234/1235 level evaluated. IC50 values were calculated using the software and a 4-parameter logistic model[1].

SAR125844 inhibited autophosphorylation of AXL and cell proliferation of TPM–NTRK1-overexpressing KM12 cell line with IC50 values of 110 and 1,400 nmol/L, respectively, indicating a 30- and 500-fold selectivity index for AXL and NTRK1 in cell-based assays. The selectivity profile of SAR125844 was further confirmed in cell lines with a single-digit nanomolar antiproliferative activity in MET-addicted cell lines and a complete lack of impact in cells not addicted to the MET pathway. This is in contrast to ARQ197 that has equal antiproliferative activity on MET-addicted and MET-independent tumor cell lines[1].

The antitumor activity of SAR125844 was investigated after administration of SAR125844 solution daily in SNU-5 bearing mice at 10, 20, and 45 mg/kg and every 2 days in Hs 746T tumor–bearing mice (at 5, 10, 20, and 45 mg/kg for SAR125844 solution and at 5, 11, 21, 53, 106, and 213 mg/kg for SAR125844 nanosuspension). Tumor volumes (in mm^3, based on the following formula, volume = length (mm) × width2 (mm2)/2), were measured twice weekly and body weight recorded every day. Endpoints collected were complete regressions (CR, regression below the palpable limit), partial regressions (PR, regression of 50% of the initial tumor volume), and the percentage of tumor regression (% of volume decrease posttreatment compared with pretreatment). Statistical significance was determined by a Dunnett test versus vehicle after a two-way ANOVA with repeated measures performed separately on ranks of changes from baseline with P < 0.05 considered significant[1].